With over one million burn injuries receiving medical treatment each year in the U.S., the social and economic costs, including recovery and reintegration burden, of burn survivors far exceed those of other injuries. Characterization of burn injuries during the early post-injury assessment period is a critical decision point in determining the management course, healing process, and ultimate outcome, since the treatment of a given burn differs considerably depending upon the results of the initial assessment. Burns are usually classified according to the depth of the damaged skin in three clinically useful categories: 1st, 2nd and 3rd degree burns. In a full-thickness or 3rd degree burn, the entire depth of the skin, through the stratum corneum, epidermis and dermis layers, is destroyed. In a partial-thickness (2nd degree) burn the extent of the damage is contained within the dermis layer. Finally, 1st degree or superficial burns only involve the epidermis layer of the skin, and usually heal without any scars or need for medical care. The clinical course of treatment is substantially different for burns of greater severity. Third degree injuries cannot heal without surgical and skin grafting procedures, whereas for 2nd degree wounds, the recovery progress consists of careful monitoring and infection prevention over a 2-3 weeks period after the burn. During this period, a subgroup of the 2nd degree burns will spontaneously heal, while others will develop to a full-thickness state and will require surgical intervention. The complex nature of partial-thickness burns is due to the extent of irreversible thermal damage to the microvasculature and the new epithelium generation sites. If an insufficient number of microvascular and epithelium generation structures survive after the injuries, the remaining viable parts of the dermis layer will slowly desiccate and eventually reach the 3rd degree injury level.
The accuracy rate of current clinical assessment technique to differentiate between burn grades, based mainly on visual inspection by experienced surgeons, is only about 65-70%. Highly accurate differentiation and delineation of burn wounds can potentially alter management, reduce length of hospital stay and improve overall recovery for the burn patient. For instance, of value would be a noninvasive clinical diagnostic modality that could guide the treatment plan by predicting the healing outcome of 2nd degree burns and guide surgical management to minimize scar formation.